4 Pectenocypris nigra, a new danionine species (Teleostei: : Danioninae) from Sumatra (Indonesia)

Arif WIBOWO1, Harald AHNELT*2, Endi S. KERTAMIHARDJA3 1Research Institute for Inland Fisheries, Agency for Marine and Fisheries Research, Ministry of Marine Affairs and Fisheries, Jl. Beringin 08 Mariana, Palembang - 30763, Indonesia. 2Department of Theoretical Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria. 3Research Center for Fisheries Management and Conservation, Agency for Marine and Fisheries Research, Ministry of Marine Affairs and Fisheries, Gedung Balitbang KP. II, Jl. Pasir Putih II, Ancol Timur 14430, Jakarta, Indonesia. *Corresponding author: [email protected]

Abstract: A new species of Danioninae, Pectenocypris nigra nov. sp. is described from peat swamps in the Riau Province, central Sumatra (Indonesia). The species differs from its congeners in the combination of the following characters: a distinct mid-lateral stripe, black spot on the base of the caudal fin, scales pale fawn with blackish margin; 28-30 scales in lateral midline, 7-10 pored lateral line scales, 160 gill-rakers on the first gill arch, and a short and deep caudal peduncle.

Keywords: Pectenocypris, , Morphology, Endemic, Indonesia. Zoobank: urn:lsid:zoobank.org:pub:7D5A7FBD-8FE6-4D93-BCF6-DE720C0D5B1D urn:lsid:zoobank.org:act:0698149F-E447-49E6-8C33-B8C2463A9B00

Introduction postorbital length (posterior most edge of the eye to the The small cyprinid Pectenocypris is currently posteriormost point of the opercle), prepectoral length (tip known to comprise three species: Pectenocypris balaena of snout to dorsal origin of the pectoral fin) and pectoral- Roberts, 1989 from western Borneo (Kalimantan Barat pelvic length (dorsal origin of pectoral fin to lateral origin Province), P. korthausae Kottelat, 1987 from southern of pelvic fin). Measurements were taken to 0.01 mm using Borneo (Kalimantan Tengah Province), and an electronic caliper and rounded to the nearest 0.1 mm. P. micromysticetus Tan & Kottelat, 2009 from Sumatra Counts and measurements were taken twice; the data are (Jambi Province) (Roberts, 1989; Doi, 1997; Tan and presented as means. The pharyngeal jaw was investigated Kottelat, 2009). All species are small (<45 mm SL) with by MicroCT imaging (for details of MicroCT imaging see a slender body and with numerous and extremely Ahnelt et al., 2015). Type specimens are deposited in the elongated gill-rakers (Kottelat, 1982; Roberts, 1989; Tan Museum Zoologicum Bogoriense (MZB), Bogor, and Kottelat 2009). Indonesia, and the Naturhistorisches Museum Wien In this paper we describe an additional species of (NMW), Vienna, Austria. Additional institutional Pectenocypris from the Serkap River drainage in central abbreviations: MHNG = Muséum d’histoire naturelle, Sumatra (Riau Province). Ville de Gèneve. Comparative material Materials and Methods Pectenocypris korthausae Kottelat, 1982; MHNG Specimens were sampled in peat lakes of the Serkap River 2073.073-075, three paratypes; 20.31-21.1 mm SL; system, Sumatra (Fig. 1). Counts and measurements Indonesia, Borneo, Kalimantan Tengah, approximately 50 follow Kottelat (2001). We also measured predorsal, to 100 km North of Sampit; collected by Mrs. Korthaus, prepelvic, preanal length and dorso-hypural distance (Tan March 1979. CAS 50488, one paratype; 20.7 mm SL; and Kottelat, 2009) and added head width (distance from same data as MHNG 2073.073-075. CAS 94171, three left to right dorsal origin of the opercular opening), specimens; 31.8-36.6 mm SL; Indonesia, Borneo, 137

ACTA BIOLOGICA TURCICA 29(4): 137-134, 2016

Figure 1. Sampling site of Pectenocypris nigra, Teluk Kapal, Sumatra. Insert: Location of Riau province (dark grey) in Sumatra.

Kalimantan Tengah, Sungai Seruyan Basin, Danau gill-rakers on first gill-arch; Kalimantnan Tengah, Sembuluh at Bangkal (-2.701715°, 112.388515°; source: Born……………………....….. Pectenocypris korthausae FishNet Collaborative Georeferencing Project); collected 3- Black spot at base of caudal fin oval; pale fawn scales by Tyson R. Roberts, 12-13 June 1992. with blackish margin; symphysal knob distinct; 160 gill- Pectenocypris balaena Roberts, 1989; CAS 49307, five rakers; Riau, Sumatra………Pectenocypris nigra sp. nov. paratypes; 23.3-28.5 mm SL; Indonesia, Borneo, - Black spot at base of caudal fin absent; dark grey scales Kalimantan Barat, Kapuas River Basin, Danau Piam near with pale fawn margin; no symphysal knob; 180-212 gill- Ketungau, 39 km NNE of Sintang (0°23'30''N, rakers; Kalimantan Barat, Borneo……………………….. 111°37'30''E); collected by Tyson R. Roberts and ……………………………………Pectenocypris balaena S. Woerjoatmodjo, 5-6 July 1976. Pectenocypris nigra, new species Results (Figs. 2-4, Table 1) Generic diagnosis: The genus Pectenocypris Kottelat, Holotype: MZB 22149; 33.1 mm SL, Indonesia, Central 1982 differs in following morphological characters from Sumatra, Riau province, peat swamp, Serkap river system, all other known genera of Cyprinidae: very long, densely river and peat lakes ‘Teluk Kapal’ (00°25'42''N, set and numerous gill rakers; shape of lower pharyngeal 102°38'45''E) aproximately 90 km east of Pelalawan; jaws tripodal; the posterior limb of each pharyngeal jaw collected by A. Wibowo and party, May 2013. with two processes (forked). Type species: Pectenocypris Paratypes: MZB 22150; 5, NMW 98607; 2, 30.2-34.2 mm korthausae Kottelat, 1982. SL; same data as holotype. Key to species of Pectenocypris: Etymology: From the Latin word niger meaning “black”. 1- Black mid-lateral stripe absent; lower jaw not or only The name refers to the blackish coloration of the species indistinctly projecting beyond upper jaw…… ……...…. 2 in life. - Black mid-lateral stripe distinct; lower jaw distinctly Diagnosis: Pectenocypris nigra sp. nov. differs from all projecting beyond upper jaw.……..………………….... 3 congeners (P. balaena, P. korthausae and 2- Black spot at base of caudal fin elongated; 165-240 gill- P. micromysticetus) by the following unique combination rakers on first gill-arch; Jambi, Sumatra………………… of characters: a distinct mid-lateral stripe; an oval black …………….……………Pectenocypris micromysticetus spot on the base of the caudal fin; scales pale fawn with - Black spot at base of caudal fin oval to roundish; 95-135 blackish margin; 28-30 scales in lateral midline; lateral 138 Wibowo et al.- Pectenocypris nigra, a new danionine species

of Cobitis avicennae

Figure 2. Pectenocypris nigra, holotype, 33.1 mm SL, lateral view. MZB 22149. Scale bar = 5 mm. (right side, reversed). Mid-lateral stripe does not extend on opercle (opercle covered by many similar sized small melanophores).

Table 1. Characters of Pectenocypris. Pb- Pectenocypris balaena, Pk- Pectenocypris korthausae, Pm- Pectenocypris micromysticetus, Pn- Pectenocypris nigra. Characters of coloration are separated from other morphological characters by a double line. ? - character not known.

Characters Pb Pm Pk Pn Scales in lateral series <30 + + - + Scales in lateral series >31 - - + - Pored lateral line scales 7-8 + + - - Pored lateral line scales 7-10 - - + + Number of gill rakers <140 - - + - Number of gill rakers <170 - - - + Number of gill rakers <220 + - - - Number of gill rakers <250 - + - - Denticles on first pharyngeal tooth ? ? + - Lower jaw distinctly projecting upper jaw + - - + Caudal peduncle long, narrow + + - - Caudal peduncle short, deep - - + + Black mid-lateral stripe distinct + - - + Black mid-lateral stripe absent or indistinct - + + - Light narrow stripe dorsal to mid-lateral stripe present - - - + Light narrow stripe dorsal to mid-lateral stripe absent + - + - Thin black mid-dorsal stripes present + + ? - Thin black mid-dorsal stripes absent - - ? + Black spot on base of caudal fin present - + + + Black spot on base of caudal fin narrow, elongate - + - - Black spot on base of caudal peduncle wide, round - - + - Black spot on base of caudal fin oval - - - + Scales light with dark margins - - + + Scales dark with light margin + + - - line incomplete, with 7-10 pored scales; 160 gill-rakers forked with pointed and elongated lobes; caudal peduncle (n=1) on the first gill arch; and a short and high caudal short, high, nearly 60% as high as long. peduncle. Measurements of holotype (33.1 mm SL) and paratypes Description: See Figure 2 for overall appearance. Body (30.1-34.2 mm SL) as percent of standard length (range slender, compressed; body depth deeper than head depth; and mean in parentheses, values of holotype in brackets): dorsal outline slightly arched, ventral outline straight; head length 26.5-28.8 (28.0) [28.2], head width at dorsal mouth terminal; jaws short; lower jaw with distinct origin of gill opening 12.4-13.4 (12.8) [13.4], head depth symphysal knob; gill rakers densely set, thin and very at nape 15.4-16.2 (16 [16.1], predorsal length 50.8-54.9 long; dorsal fin originates above or slightly before pelvic (52.7) [54.6], prepelvic length 51.8-54.1 (52.9) [53.6], fin; pectoral fin long, roundish, reaching about 75% of preanal length 72.2-75.7 (74.1) [74], prepectoral length distance to pelvic fin; depressed tip of the first (longest) 28.0-29.7 (28.7) [29.2], pectoral-pelvic length 24.0-25.2 pelvic fin ray reaches origin of anus; caudal fin distinctly (24.3) [24.9], pectoral fin length 16.6-17.9 [17.8], body

139 ACTA BIOLOGICA TURCICA 29(4): 137-134, 2016

first gill arch. Gill-rakers and gill filaments of about the same length. Vertebral count (n=2): 32; 17 precaudal+15 caudal vertebra. The pharyngeal jaws (n=2) are of a tripodal shape (Fig. 4). The posterior limb of each pharyngeal jaw is forked ending in two distinct processes. Three teeth are attached perpendicularly on the medial side of the tooth-bearing process and are arranged in a single row (tooth formula 3- 3). The shape of the pharyngeal jaws and the pharyngeal teeth of P. nigra are similar to those of P. korthausae (Kottelat, 1982; Fig. 1) and to P. balaena (Roberts, 1989). But contrary to P. korthausae, no pharyngeal tooth of Figure 3. Pectenocypris nigra, holotype, head, lateral view. MZB P. nigra has denticles. The shape of the pharyngeal jaws 22149. Scale bar = 0.5 mm. Note whitish symphysial knob on and the pharyngeal dentition of P. micromysticetus are not lower jaw and extension of mid-lateral stripe on opercle (large known (Tan and Kottelat, 2009). roundish melanophores in upper half of opercle). Coloration: Living specimens (from observations during depth at dorsal fin origin 18.4-20.2 (19.3) [18.8], caudal sampling) are black on the dorsal side, somewhat lighter peduncle depth 10.1-11 (10.6) [11], caudal peduncle on the ventral side, with a distinct black mid-lateral stripe length 17.7-18.6 (17.8) [18.2], snout length 7.2-8.1 (7.5) ending in a black oval black spot. Preserved specimens are [7.7], eye diameter 7.7-8.9 (8.4) [8.4], postorbital length blackish on the dorsal side and light grey to fawn on the 10.9-11.8 (11.4) [11.6], interorbital width 9.6-10.6 (10.0) ventral side. A distinct black mid-lateral stripe runs from [10.0], dorso-hypural distance 49.2-50.6 (49.7 [49.5]. As the posterior margin of the opercle to the base of the percentage of head length: snout length 27.3-28.6 (27.8) caudal fin. Mid-lateral stripe not (holotype, three [27.4], eye diameter 29.1-31.8 (31.0) [29.6], interorbital paratypes) or indistinctly (three paratypes) extending on width 34.4-38.1 (36.0) [35.6], postorbital length 41.2-42.8 the opercle; in latter case, many melanophores form a (41.3) [42.5]. As percentage of eye diameter: interorbital diffuse dark area on opercle (Fig. 2). Mid-lateral stripe width 114.0-118.9 (116.7) [118.9]. As percentage of ends at distinct black oval spot at base of caudal fin. caudal peduncle length: caudal peduncle depth 58.2-61.7 Dorsal sides of head (including snout) and trunk very dark (59.6) [58.6]. with blackish mid-dorsal line from base of last dorsal fin Counts of holotype and paratypes (values of holotype are to dorsal origin of caudal fin. Conspicuous symphysial indicated by an asterisk (*), in parentheses each value is knob on lower jaw whitish (holotype, four paratypes) or followed by a colon and by the number of specimens bright white (three paratypes), distinctly contrasting with respectively): dorsal fin with 2 simple and 6½ to 7½ blackish upper lip and head (Fig. 3). Trunk ventral to mid- branched rays (6½: 1, 7*: 5, 7½: 1); anal fin with 3 simple lateral stripe fawn to light grey. Fawn stripe immediately and 5½ branched rays (5½*: 8); pectoral fin with 1 simple dorsal to mid-lateral stripe. These lighter areas, enclosing and 12 to 13 branched rays (12*: 4, 13: 4); pelvic fins with the mid-lateral stripe, accentuate its black color (Fig. 2). 1 simple and 7 to 8 branched rays (7: 3, 8*: 5); caudal fin Thin black mid-axial streak accompanies mid-lateral deeply forked with 18 to 19 principle rays (18: 1, 19*: 7), stripe from below dorsal fin close to caudal spot. Margins 16-17 of them branched (16: 1, 17*: 7) (from dorsal to of scales dark grey pigmented, yielding distinct reticulate ventral: 1/8+8/1 or 1/9+8/1). Scales in lateral series 27+1- pattern which is more pronounced dorsal to mid-lateral 28+2 (27+1: 1, 27+2: 1, 28+2*: 6); lateral line incomplete, stripe. Blackish mid-ventral streak from last anal fin ray pored scales left/right 7/7-9/10 (7/7: 1, 8/9: 2, 9/8: 1, 9/9:1, to ventral origin of caudal fin. No black streak on base of 10/9*: 2, 10/10:1); predorsal scales 11-12 (11*: 7,12: 1); anal fin. Black melanophores follow course of all fin rays, scales in transversal series from origin of dorsal fin most densely covering rays of paired and dorsal fins. Gill rearwards and downwards 7.5-8.5 (7.5: 1, 8.5*: 7); scales filaments light fawn, covered by one distinct black spot in circumpeduncular series 11-12 (11: 6, 12*: 2). Gill- (short filaments) or by a row of up to five distinct black rakers (n=1): 50 on the upper, 110 on the lower arm of the spots extending on gill filaments (except on the very short 140 Wibowo et al.- Pectenocypris nigra, a new danionine species

of Cobitis avicennae

Figure 3. Pectenocypris nigra, paratype, NMW 98607, 30.2 mm SL. Right lower pharyngeal jaw, lateral view (A), medial view (B). Tooth crown of a replacement tooth indicated by arrowhead. a=anterior. filaments at the origin of the ceratobranchial and the end (characters in parentheses), a species also with a distinct of the epibranchial) giving gills a spotted pattern. black mid-lateral stripe, by a wide and oval black spot on Ecology: Pectenocypris nigra is currently only known the base of the caudal fin (vs. no black spot; some from peat swamps surrounded by prestine forest. The specimens with “a small dark area at the very end of the water quality is characterized by acid waters (pH of 3.2- stripe” (Roberts, 1989)) and by light fawn scales with dark 4.3; values classified as ultra to extremely acid, by low brown margins (vs. dark grey scales with light fawn dissolved oxygen (1.3-5.9 ppm) and a water transparency margins, 160 gill-rakers on the first gill arch (vs. 180-212 of 50-100 cm. The color of the water is tannin-stained dark gill-rakers [Roberts (1989) stated that the lower number brown. Pectenocypris nigra is seemingly the only species of gill-rakers (180) is “… possibly somewhat too low due of the genus occurring in peat swamps with a pH classified to the minute size of the gill-rakers at the ends of the upper as ultra to extremely (Bird, 2004) acid. In contrast, and lower limits of the gill arch.”]), deeper caudal P. balaena “inhabits small forest streams” (Roberts, 1989) peduncle, 17.8 % in SL (vs. 10.7 %) and a smaller eye, 8.4 having a pH of 5-5.6 (accessed from “www.calacademy % in SL (vs. 12.0 %). Pectenocypris balaena is currently .org/scientists/ichthyology-collections” on 10.06.2016). only known from Borneo. The pH values of the waters inhabited by P. korthausae Pectenocypis nigra is distinguished from and P. micromysticetus are not known. Pectenocypris P. micromysticetus (characters in parentheses) by the korthausae was “collected in a flooded forest” (Kottelat, presence of a distinct mid-lateral strip (vs. absent or very 1982), and P. micromysticetus occurs “in oxbow lakes and indistinct mid-lateral stripe), light fawn scales with dark still pools in open or recently flooded areas” and grey margin (vs. yellowish brown scales with fawn seemingly not in peat swamp areas (Tan and Kottelat, margin), 160 gill-rakers on the first gill arch (vs. 240 gill- 2009, Fig. 1). rakers), caudal peduncle shorter, 17.8% in SL (vs. 20.2 Distribution: Pectenocypris nigra is presently only known %), larger eye, 31 % in head length (vs. 28.2 %) and larger from river and peat lakes ‘Teluk Kapal’ of the Serkap interorbital width, 36 % in head length (vs. 32.7 %). Both River system in the Riau Province of Central Sumatra. species are presently only known from Sumatra. Remarks: Comparison with the three congeners: Pectenocypris nigra is distinguished from Pectenocypris nigra is distinguished from P. balaena P. korthausae (characters in parentheses) by a distinct 141 ACTA BIOLOGICA TURCICA 29(4): 137-134, 2016

mid-lateral stripe (vs. absent mid-lateral stripe), an oval References spot at the base of the caudal fin (vs. roundish spot), thin Ahnelt H., Herdina A.N., Metscher B.D. 2015. Unusual black mid-axial streak extending on posterior half of body pharyngeal dentition in the African Chedrin (vs. thin mid-axial streak extending along the entire body), (Teleostei: Cyprinidae): Significance for phylogeny no denticles on the pharyngeal teeth (vs. three denticles on and character evolution. Zoolgischer Anzeiger, 255: the anterior-most pharyngeal tooth) (Fig. 4), the lower jaw 85-102. distinctly projecting beyond the upper jaw (vs. lower jaw Bird R. 2004. Soil Survey Laboratory. Methods Manual. indistinctly projecting beyond the upper jaw), the lower Chapter Three. Natural Resources Conservation jaw with a distinct symphysal knob (vs. no such distinct Service. United States Department of Agriculture symphysal knob), lower number of circumpeduncular (accessed 06.06.2016). scales, 11-12 (vs. 14), 160 gill-rakers on the first gill arch Doi A. 1997. A review of taxonomic studies of (vs. max. 135 gill-rakers), its larger size, 30.1-34.2 mm SL cypriniform fishes in South-east Asia. Japanese (vs. 21.5-30 mm SL), longer predorsal distance, 52.7 % in Journal of Ichthyology, 44: 1-33 [in Japanese]. SL (vs. 50.8 %), longer head, 28.0 % in SL (vs. 26.1 %), Kottelat M. 1987. A small collection of fresh-water fishes longer snout, 7.5 % in SL (vs. 6.1 %) and a smaller eye, from Kalimantan, Borneo, with descriptions of one 31.0 % in head length (vs. 33.4 %) (Table 1). new genus and three new species of Cyprinidae. Revue Pectenocypris korthausae resembles in coloration P. nigra Suisse de Zoologique, 89: 419-437. in the combination of a black spot at the base of the caudal Kottelat M. 2001. Fishes of Laos. Colombo, WHT fin and scales with a dark margin, brown in P. korthausae Publications. 198 p. and blackish in P. nigra. Pectenocypris korthausae is Roberts T.R. 1989. The freshwater fishes of western currently only known from Borneo. Borneo (Kalimatan Barat, Indonesia). Memoires of the Gill-raker number is increasing with size in P. balaena California Academy of Sciences, Scientific Series, 14: (Roberts, 1989), P. korthausae and P. micromysticetus 1-210. (Tan and Kottelat, 2009). Therefore we compared the gill- Tan H.H., Kottelat M. 2009. The fishes of Batang Hari raker number of similar sized specimens of all four drainage, Sumatra, with descriptionof six new species. Pectenocypris species to exclude a possible size bias by Ichthyological Explorations of Freshwaters, 20: 13-69. size. Actually the gill-raker number differs distinctly between similar sized specimens. The lowest number occurs in P. korthausae (135 gill-rakers; 30 mm SL) (Tan and Kottelat, 2009), followed by P. nigra (160 gill-rakers; 30.2 mm SL) (this study), P. micromysticetus (205 gill- rakers; 32.5 mm SL) (Tan and Kottelat, 2009) and, with the highest number P. balaena (212 gill-rakers; 30.1 mm SL) (Roberts, 1989). These gill-raker numbers are also the maximum number except for P. micromysticetus. This species reaches a size of approximately 45 mm SL with up to 240 gill-rakers.

Acknowledgements We thank Sonia Fisch-Muller (MHNG) for the loan of paratypes of Pectenocypris korthausae, Dave Catania and Jon Fong (California Academy of Sciences) for providing photographs of type and non-type material of Pectenocypris balaena and Pectenocypris korthausae, Brian D. Metscher and Anna N. Herdina for microCT imaging the pharyngeal structures, and M. Stachowitsch for improving the English. 142